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more simplification rules
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@wildart
wildart committed Dec 20, 2021
1 parent f7a0362 commit b0f5477
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Showing 2 changed files with 123 additions and 26 deletions.
112 changes: 95 additions & 17 deletions src/api/expressions.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -86,6 +86,8 @@ isonenum(root) = isnum(root) && isone(root)
isdiv(ex) = ex in [/, div, pdiv, aq]
isexpr(ex) = isa(ex, Expr)
issym(ex) = isa(ex, Symbol)
isexprsym(ex) = isexpr(ex) || issym(ex)
isbinexpr(ex) = isexpr(ex) && length(ex.args) == 3

function evaluate(ex::Expr, psyms::Dict{Symbol,Int}, vals::T...)::T where {T}
exprm = ex.args
Expand Down Expand Up @@ -136,24 +138,100 @@ function simplifybinary!(root)
elseif (fn == (+)) && (op1 == op2) # x+x = 2x
root.args[1] = (*)
root.args[2] = 2
elseif (fn == (+) || fn == (-))
# n1+(n2+x) = n1+(x+n2) = (n2+x)+n1 = (x+n2)+n1 = x+n3, s.t. n3=n1+n2
if (isexpr(op1) && isnum(op2)) || (isnum(op1) && isexpr(op2))
# swap so op1 is expr
if isnum(op1) && isexpr(op2)
op1, op2 = op2, op1
elseif (fn == (+) || fn == (-)) && (isbinexpr(op1) && isnum(op2))
fn2, op11, op12 = op1.args
if fn == (+) && fn2 == (-) && isnum(op12)
# (x-m)+n = x+(n-m)
root.args[2] = op11
root.args[3] = op2-op12
elseif fn == (-) && fn2 == (-) && isnum(op12)
# (x-m)-n = x-(n+m)
root.args[2] = op11
root.args[3] = op12+op2
elseif fn2 == (+) && (isnum(op11) || isnum(op12))
# (m+x)±n = (x+m)±n = x+(n±m)
var, n2 = isnum(op11) ? (op12, op11) : (op11, op12)
n3 = fn(n2, op2)
root.args[1] = fn2
root.args[2] = var
root.args[3] = n3
elseif fn2 == (-) && isnum(op11)
# (m-x)±n = (n±m)-x
n3 = fn(op11, op2)
root.args[1] = fn2
root.args[2] = n3
root.args[3] = op12
end
elseif fn == (+) && isnum(op1) && isbinexpr(op2)
fn2, op21, op22 = op2.args
if fn2 == (+) || fn2 == (-)
if isnum(op21)
# n+(m±x) = (n+m)±x
root.args[1] = fn2
root.args[2] = op1 + op21
root.args[3] = op22
elseif isnum(op22)
# n+(x±m) = (n±m)+x
root.args[1] = fn
root.args[2] = fn2(op1, op22)
root.args[3] = op21
end
end
elseif fn == (-) && isnum(op1) && isbinexpr(op2)
fn2, op21, op22 = op2.args
if fn2 == (+) && (isnum(op21) || isnum(op22))
# n-(x+m) = n-(m+x) = (n-m)-x
var, n2 = isnum(op21) ? (op22, op21) : (op21, op22)
root.args[2] = op1 - n2
root.args[3] = var
elseif fn2 == (-) && (isnum(op21) || isnum(op22))
# n-(m-x) = (n-m)+x
# n-(x-m) = (n+m)-x
var, n2, f1p = isnum(op21) ? (op22, op21, true) : (op21, op22, false)
root.args[1] = f1p ? (+) : (-)
root.args[2] = f1p ? op1 - n2 : op1 + n2
root.args[3] = var
end
elseif fn == (+) && (isexpr(op1) || isexpr(op2))
if isbinexpr(op2)
# x + (n - x) = n
fn2, op21, op22 = op2.args
if fn2 == (-) && op1 == op22
root = op21
end
elseif isbinexpr(op1)
# (n - x) + x = n
fn2, op11, op12 = op1.args
if fn2 == (-) && op12 == op2
root = op11
end
end
elseif fn == (-) && (isexpr(op1) || isexpr(op2))
if isbinexpr(op2)
fn2, op21, op22 = op2.args
if op1 == op21
# x - (x ± n) = -±n
if fn2 == (-)
root = op22
else
pop!(root.args)
root.args[end] = op22
end
elseif op1 == op22 && fn2 == (+)
# x - (n + x) = -n
pop!(root.args)
root.args[end] = op21
end
#println("ex1: $fn ($op1, $op2)"
# op2 is binexpr
if isexpr(op1) && length(op1) == 3
fn2, op21, op22 = op1.args
# some operand has to be num
if (fn2 == (+) || fn2 == (-)) && (isnum(op21) || isnum(op22))
var, n2 = isnum(op21) ? (op22, op21) : (op21, op22)
n3 = fn(n2, op2)
elseif isbinexpr(op1)
# (x ± n) - x = ±n
fn2, op11, op12 = op1.args
if op11 == op2
if fn2 == (+)
root = op12
else
root.args[1] = fn2
root.args[2] = var
root.args[3] = n3
root.args[2] = op12
pop!(root.args)
end
end
end
Expand Down Expand Up @@ -196,7 +274,7 @@ function infix(io::IO, root; digits=3)
print(io, "(")
infix(io, root.args[2])
infix(io, root.args[1])
infix(io, root.args[3])
length(root.args)>2 && infix(io, root.args[3])
print(io, ")")
else
infix(io, root.args[1])
Expand Down
37 changes: 28 additions & 9 deletions test/gp.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@
@testset for (func, arity) in t.functions
@test arity == 2
end
@test_skip summary(t) == "TreeGP[P=10,Parameter[x,y],Function[*, +, /, -]]"
show(IOBuffer(), summary(t))

# population initialization
popexp = Evolutionary.initial_population(t, rng=rng);
Expand All @@ -36,16 +36,16 @@
@test Evolutionary.nodes(ft) == 15
@test Evolutionary.height(ft) == 3
@test length(ft) == 15
# @test Evolutionary.depth(ft, :x) == 3
# ft[3] = :z
# @test Evolutionary.depth(ft, :z) == 3
@test Evolutionary.depth(ft, :x) == 3
ft[3] = :z
@test Evolutionary.depth(ft, :z) == 3
@test Evolutionary.depth(ft, ft) == 0
@test Evolutionary.depth(ft, ft[3]) > 0
@test Evolutionary.depth(ft, :w) == -1
@test Evolutionary.evaluate([1.0, 2.0], :y, [:y, :z]) == 1.0
@test Evolutionary.evaluate(:y, Dict(:y=>1, :z=>2), 1.0, 2.0) == 1.0
copyto!(ft, gt)
@test ft == gt
# @test Evolutionary.symbols(ft) |> sort == [:x, :y]
@test Evolutionary.symbols(ft) |> sort == [:x, :y]

# simplification
using Evolutionary: simplify!
Expand All @@ -64,8 +64,27 @@
@test Expr(:call, log, Expr(:call, exp, 1)) |> simplify! == 1
@test Expr(:call, -, Expr(:call, +, :x, 1), 2) |> simplify! == Expr(:call, +, :x, -1)
@test Expr(:call, -, Expr(:call, +, 1, :x), 2) |> simplify! == Expr(:call, +, :x, -1)
@test Expr(:call, +, 2, Expr(:call, +, 1, :x)) |> simplify! == Expr(:call, +, :x, 3)
@test Expr(:call, +, 2, Expr(:call, +, :x, 1)) |> simplify! == Expr(:call, +, :x, 3)
@test Expr(:call, +, Expr(:call, +, :x, 1), 2) |> simplify! == Expr(:call, +, :x, 3)
@test Expr(:call, +, Expr(:call, +, 1, :x), 2) |> simplify! == Expr(:call, +, :x, 3)
@test Expr(:call, +, Expr(:call, -, 1, :x), 2) |> simplify! == Expr(:call, -, 3, :x)
@test Expr(:call, -, Expr(:call, -, 1, :x), 2) |> simplify! == Expr(:call, -, -1, :x)
@test Expr(:call, +, Expr(:call, -, :x, 1), 2) |> simplify! == Expr(:call, +, :x, 1)
@test Expr(:call, -, Expr(:call, -, :x, 1), 2) |> simplify! == Expr(:call, -, :x, 3)
@test Expr(:call, +, :x, Expr(:call, -, 1, :x)) |> simplify! == 1
@test Expr(:call, +, Expr(:call, -, 2, :x), :x) |> simplify! == 2
@test Expr(:call, -, :x, Expr(:call, +, :x, :y)) |> simplify! == Expr(:call, -, :y)
@test Expr(:call, -, :x, Expr(:call, -, :x, :y)) |> simplify! == :y
@test Expr(:call, -, :x, Expr(:call, +, :y, :x)) |> simplify! == Expr(:call, -, :y)
@test Expr(:call, -, Expr(:call, -, :x, :y), :x) |> simplify! == Expr(:call, -, :y)
@test Expr(:call, -, Expr(:call, +, :x, :y), :x) |> simplify! == :y
@test Expr(:call, +, 2, Expr(:call, +, 1, :x)) |> simplify! == Expr(:call, +, 3, :x)
@test Expr(:call, +, 2, Expr(:call, -, 1, :x)) |> simplify! == Expr(:call, -, 3, :x)
@test Expr(:call, +, 2, Expr(:call, +, :x, 1)) |> simplify! == Expr(:call, +, 3, :x)
@test Expr(:call, +, 2, Expr(:call, -, :x, 1)) |> simplify! == Expr(:call, +, 1, :x)
@test Expr(:call, -, 2, Expr(:call, +, 1, :x)) |> simplify! == Expr(:call, -, 1, :x)
@test Expr(:call, -, 2, Expr(:call, +, :x, 1)) |> simplify! == Expr(:call, -, 1, :x)
@test Expr(:call, -, 1, Expr(:call, -, 2, :x)) |> simplify! == Expr(:call, +, -1, :x)
@test Expr(:call, -, 2, Expr(:call, -, :x, 1)) |> simplify! == Expr(:call, -, 3, :x)

# evaluation
ex = Expr(:call, +, 1, :x) |> Evolutionary.Expression
Expand Down Expand Up @@ -100,7 +119,7 @@
ε = 0.1
),
),
Evolutionary.Options(show_trace=true, rng=rng, iterations=50)
Evolutionary.Options(show_trace=false, rng=rng, iterations=50)
)
@test minimum(res) < 1.1

Expand Down

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